Even U.S. Pat. No. 4,817,664 issued to the same applicant, Z. S. Chang of this application and U.S. Pat. No. 4,195,656 issued Kanerva's et al., all disclosed a pressure regulator for automatically shutting off a throttle nozzle of the regulator in case of excess gas flow or a gas leakage caused in a gas line, such a conventional gas regulator should require a small tensioning spring (numeral "263" of Chang's patent or "106" of Kanerva's patent) for normally urging a valve reciprocatively held in an orifice of the throttle nozzle, thereby increasing the adjustment problems for adjusting a pressure in a gas reduced chamber. Especially after a time period of practical use, the springs may have fatigve failure to further increase the difficulty for adjusting the pressure in the gas reduced chamber, thereby influencing its operation and maintenance.
The present inventor has found the drawbacks of the conventional gas regulator having spring-loaded throttle nozzle and invented the present gas pressure regulator.